In continuous casting and metals, such as brass and the like, it is common to permit molten metal to flow from a crucible through a die which is surrounded by a cooling apparatus so that the molten metal progressively solidifies and is withdrawn by suitable apparatus. A major consideration in the efficiency of such a device is the ability to remove heat from the die. In order to provide a satisfactory cast product, it is necessary that in the area where the molten metal begins to solidify, commonly known as the freezing zone, a strong outer skin be formed on the outer surface of the product being formed and that the meniscus of the molten metal should be very flat or shallow so that the heat will not be carried further down toward the outlet and tend to re-melt the solidified outer skin adversely affecting the product and possibly resulting in interruption of production.
A prior efficient apparatus for cooling the die utilizes a cooling sleeve having intimate contact with the exterior surface of the die, which cooling sleeve is externally cooled by flowing coolant about the periphery thereof. Inasmuch as the coolant that first contacts the cooling sleeve is cold and progressively increases in temperature, there is a tendency for the cooling sleeve to be cooled unevenly and expand out of intimate contact with the die at that point.
Among the objects of the invention are to provide a novel cooler assembly which provides increased cooling action by facilitating turbulent flow of the cooling liquid, slows the velocity of the coolant and uniformly increases the temperature from the area of intake to exhaust which increases the area of coolant surfaces without sacrificing strength of the cooling sleeve which increased cooling exchange is achieved at a low cost by permitting the coolant to increase in temperature at a unit time; and which invention can be readily adapted to conventional die and cooler assemblies for casting aluminum, copper alloys and all ferrous and non-ferrous metal.
In accordance with the invention, a continuous casting apparatus comprises a cooler body surrounding a graphite die and having a plurality of integral grooves on an outer surface thereof defining ribs, and a shell or a plate enclosing the grooves to define axial passages. The ribs have longitudinally spaced recesses in the form of semicircles on the edges of the ribs and indentations greater than the depth of the rib, whereby coolant moving along the axial passages is subjected to a turbulent flow. The coolant moving along the ribs enters the recesses and indentations and expands from the heat and is forced out to provide a continuous agitation of the coolant flow changing the speed of the moving coolant along the ribs and along the axial passages. The recesses have enlarged cross section or diameter greater than diameter of the axial passages so that coolant entering the enlarged cross sections expands and provides a continuous agitation of the moving coolant, changing the speed of the moving coolant for better heat transfer from the cooler body to the coolant and consequently from the graphite die where it is used and from the product being formed or directly from the product being formed without sacrificing strength of the cooler body.